Flotation reducing slurry, preparation method thereof and floatation reducing method
By using water, bentonite, foaming agent and stabilizer in large-diameter directional drilling and back-drag, and combined with grouting system control, the problem of long construction period and high cost caused by complex PE pipe processes is solved, and time-travel is achieved The net buoyancy of the pipe in the hole is accurately controlled, which improves the construction efficiency and floating reduction effect.
Patent Information
- Application Number
- CN202310836734.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-10
- Publication Date
- 2025-01-10
AI Technical Summary
In the prior art, the process of using PE pipes to reduce the float is complicated, resulting in a long construction period, high cost, and insufficient precision in floating reduction. Especially during the large-diameter directional drilling and dragging process, the net buoyancy of the through-pipe in the hole is difficult to accurately control.
A floating-reducing slurry is used, with a ratio of water, bentonite, foaming agent and stabilizer. It is prepared by stirring foaming. The target density and half-life are adjustable. The crossing tube is injected to reduce the net buoyancy. Combined with the control of the grouting system, it ensures that Net buoyancy within ±0.1kN/m.
It significantly shortens the construction period and reduces costs, ensures that the cross-border pipe is suspended and stable during the tow back, avoids the installation and disassembly of the PE pipe, and improves the accuracy of the floating reduction effect.
Smart Images
Figure CN119286480A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of horizontal directional drilling, and in particular relates to a flotation reduction slurry and a preparation method thereof, and a flotation reduction method. Background Art
[0002] When the net buoyancy of the pipeline in the borehole is greater than 2kN / m, measures must be taken to reduce the buoyancy. Reducing the buoyancy refers to reducing the upward net buoyancy of the crossing pipe in the borehole.
[0003] When pulling back a large-diameter directional drill, a PE pipe for reducing buoyancy is usually installed in the crossing pipeline, and then water is filled inside or outside the PE pipe to reduce buoyancy. This measure can reduce the buoyancy to less than 2kN / m. There are two ways to install PE pipes: multiple pipes and single pipe. Figure 1 and attached Figure 2 shown.
[0004] In the attached Figure 1 and attached Figure 2 In the present invention, multiple or single PE pipes 2 are arranged in the pull-back pipeline 1, and a water injection pipe 4 is arranged in the PE pipe 2. Clean water 3 injected into the PE pipe 2 through the water injection pipe 4 reduces the upward net buoyancy of the crossing pipe.
[0005] It can be seen that the structure inside the crossing pipe is complex, and the installation process of PE pipe in the limited operating space is complicated and difficult to operate. It is necessary to arrange a professional team to use special equipment for welding and removal, which affects the construction period and cost. In addition, during the water injection process, each time the water injection pump stops, part of the water in the water injection pipe will flow back due to the pressure difference and high pump pressure, resulting in inaccurate water injection for lowering the buoyancy; at the same time, due to the influence of the PE pipe process characteristics, the amount of lowering the buoyancy cannot be accurately controlled during the back-pulling process of the transition from the curved section to the horizontal section, which may affect the lowering effect. Summary of the invention
[0006] The disclosed embodiments provide a defloating slurry, a method for preparing the defloating slurry, and a defloating method for horizontal directional drilling pipeline crossing and backhauling, so as to solve the problems of the existing PE pipe defloating process being complicated, resulting in a long construction period, high cost, and inaccurate defloating.
[0007] A first aspect of an embodiment of the present disclosure provides a buoyancy-reducing slurry for injection into a crossing pipe to reduce the net buoyancy of a large-diameter directional drill during its pullback, characterized in that the slurry comprises the following proportions (by weight): water, bentonite (4%-6%), a foaming agent (0.1%-0.3%) and a stabilizer (0.05%-0.2%).
[0008] Preferably, the slurry further comprises soda ash.
[0009] A second aspect of the embodiments of the present disclosure provides a method for preparing a deflocculation slurry, comprising:
[0010] Determining a target density and a target half-life of the desludging slurry, wherein the density of the desludging slurry is stable during the target half-life;
[0011] Adjusting the ratio of the desaturation slurry of the first aspect of the present disclosure to achieve the target density and the target half-life;
[0012] The deflocculation slurry of the proportion is stirred and foamed at a stirring speed of 2000 rpm to obtain the deflocculation slurry having the target density and the target half-life.
[0013] In some embodiments of the present disclosure, determining the target half-life of the dewatering slurry comprises:
[0014] The target half-life is not less than the directional drilling backhaul time.
[0015] In some embodiments of the present disclosure, determining the target density of the deflocculation slurry comprises:
[0016] The target net buoyancy of the crossing pipe in the hole is determined and the mud density in the hole outside the crossing pipe is obtained, and the target density of the debuoyancy slurry is determined based on the target net buoyancy and the mud density.
[0017] In some embodiments of the present disclosure, adjusting the ratio of the deflocculation slurry in the first aspect of the present disclosure to achieve the target density and the target half-life includes:
[0018] Soda ash is added to the desaturated slurry, and the density and half-life of the desaturated slurry are increased by increasing the content of the soda ash until the target density and the target half-life are reached.
[0019] A third aspect of the disclosed embodiment provides a floating lowering method, which is applied to large-diameter directional drilling pipeline crossing and pulling back construction, comprising:
[0020] Prepare the desludging slurry according to the method described in the second aspect of the present disclosure;
[0021] When the large-diameter directional drill is pulled back, the debuoyancy slurry is injected into the crossing pipe so that the net buoyancy of the crossing pipe in the hole is within ±0.1 kN / m.
[0022] In some embodiments of the present disclosure, injecting a flotation-reducing slurry into the crossing pipe includes:
[0023] When the large-diameter directional drill is towed back, the grouting pipe head is passed through the catback into the crossing pipe and then the defloating slurry is injected into the crossing pipe through the grouting pipe head.
[0024] In some embodiments of the present disclosure, injecting the defloating slurry into the crossing pipe through the grouting pipe head comprises:
[0025] The grouting pipe is extended into the position of the pipeline pulling head for fixed-point grouting.
[0026] In some embodiments of the present disclosure, injecting the flotation reduction slurry into the crossing pipe further comprises:
[0027] By controlling the grouting speed and grouting amount, it is ensured that the liquid level in the crossing pipe is always lower than the cat back apex.
[0028] In summary, the debuoyancy slurry, the preparation method of the debuoyancy slurry, and the debuoyancy method during the horizontal directional drilling pipeline crossing and backhauling provided by the embodiments of the present disclosure reduce the net buoyancy of the crossing pipe in the hole by injecting the debuoyancy slurry into the crossing pipe. Because the debuoyancy slurry is injected through the grouting system, the debuoyancy slurry can be configured in advance on site and injected as needed. After the construction is completed, the debuoyancy slurry can be removed by cleaning the pipe. The construction is quick and simple, and there is no need to install or disassemble the PE pipe, thereby significantly shortening the construction period and reducing costs. Because the net buoyancy of the crossing pipe can be reduced to basically 0 by adjusting the density of the debuoyancy slurry, it is ensured that the pipeline is always suspended in the hole during the backhauling process; the backhauling pipeline is filled with the debuoyancy slurry to form a solid overall stable structure, and the debuoyancy effect will not be affected by the horizontal and longitudinal position changes of the pipeline during the backhauling process; the starting position of the injection is in front of the cat's back, so that it can not only ensure that the pipeline towed into the hole is in a suspended state in the mud after grouting, but also ensure that the pipeline behind the cat's back floats on the water surface of the sending ditch, so that a more accurate debuoyancy effect can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The features and advantages of the present disclosure will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present disclosure in any way. In the accompanying drawings:
[0030] Figure 1 This is a schematic diagram of using multiple PE pipes to lower the float when pulling back a large-diameter directional drill;
[0031] Figure 2 This is a schematic diagram of using a single PE pipe to lower the float when pulling back a large-diameter directional drill;
[0032] Figure 3 is a flow chart of a method for preparing a desludging slurry as shown in some embodiments of the present disclosure;
[0033] Figure 4 It is a calculation table for the density of the deflocculation slurry at the construction site shown in some embodiments of the present disclosure;
[0034] Figure 5 It is the experimental data of the flotation slurry stabilization experiment configured in the construction site shown in some embodiments of the present disclosure;
[0035] Figure 6 is a flow chart of a method for lowering and floating a horizontal directional drilling pipeline during a crossing and backhauling as shown in some embodiments of the present disclosure;
[0036] Figure 7 It is a schematic diagram of a horizontal directional drilling pipeline crossing and pulling back construction site shown in some embodiments of the present disclosure.
[0037] List of reference numerals:
[0038] 1 return line, 2 PE pipe, 3 clean water,
[0039] 4 water injection pipe, 5 mud pump, 6 mud tank,
[0040] 7 Mud high pressure pipe, 8 Flow valve, 9 Butterfly valve,
[0041] 10 grouting pipe, 11 catback, 12 through pipe,
[0042] 13. Floating slurry, 14. Drill pipe. DETAILED DESCRIPTION
[0043] In the detailed description below, many specific details of the present disclosure are set forth by way of example in order to provide a thorough understanding of the relevant disclosure. However, it will be apparent to one of ordinary skill in the art that the present disclosure can be implemented without these details. It should be understood that the use of the terms "system," "device," "unit," and / or "module" in the present disclosure is a method for distinguishing different parts, elements, parts, or assemblies at different levels in a sequential arrangement. However, these terms may be replaced by other expressions if other expressions can achieve the same purpose.
[0044] It should be understood that when a device, unit or module is referred to as being "on," "connected to," or "coupled to" another device, unit or module, it may be directly on, connected to, coupled to, or communicating with other devices, units or modules, or there may be intermediate devices, units or modules, unless the context clearly indicates an exception. For example, the term "and / or" as used in this disclosure includes any and all combinations of one or more of the relevant listed items.
[0045] The terms used in this disclosure are only for describing specific embodiments and are not intended to limit the scope of this disclosure. As shown in the specification and claims of this disclosure, unless the context clearly indicates an exception, the words "one", "a kind" and / or "the" do not specifically refer to the singular, but may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of clearly identified features, wholes, steps, operations, elements and / or components, and such expressions do not constitute an exclusive list, and other features, wholes, steps, operations, elements and / or components may also be included.
[0046] Some embodiments of the present disclosure disclose a debuoyancy slurry injected into a crossing pipe to reduce the net buoyancy of a large-diameter directional drill when it is pulled back. The basic ratio of the debuoyancy slurry is (by weight): water, bentonite (4%-6%), foaming agent (0.1%-0.3%) and stabilizer (0.05%-0.2%).
[0047] In some embodiments of the present disclosure, soda ash can be added on the basis of the basic ratio to increase the slurry density, extend the half-life of the slurry, and adjust the uniformity of foaming.
[0048] In order to reduce the net buoyancy of the crossing pipe in the hole to within ±0.1 kN / m after the crossing pipe is injected, the density of the debuoyancy slurry needs to be controlled at (0.5 g / ml-0.8 g / ml), and the half-life is not shorter than the time required for directional drilling backhaul (24-72 hours). The density of the debuoyancy slurry is stable during the half-life.
[0049] In some embodiments of the present disclosure, the ratio, density and half-life of different deflocculation slurries are as follows:
[0050] Example 1: 500ml water + 25g soil + 2g foaming agent + 2g CMC, density is 0.49g / ml, which can achieve stability during the directional drilling pullback period (24-72 hours).
[0051] Example 2: 500ml water + 25g soil + 1g foaming agent + 1g CMC, density is 0.65g / ml, which can achieve stability during the directional drilling pullback period (24-72 hours).
[0052] Example 3: 500ml water + 25g soil + 1g foaming agent + 1g CMC + 0.8g soda ash, density is 0.66g / ml, which can achieve stability during the directional drilling pullback period (24-72 hours).
[0053] Some other embodiments of the present disclosure disclose a method for preparing a desludging slurry. Figure 3 Flow chart of the method for preparing the desludging slurry. Figure 3 As shown, the method includes:
[0054] S310: Determine a target density and a target half-life of the desludging slurry, wherein within the target half-life, the density of the desludging slurry is stable.
[0055] S320: Adjust the ratio of the desludging slurry to achieve the target density and the target half-life.
[0056] S330: stirring and foaming the prepared desufflation slurry at a stirring speed of 2000 rpm to obtain the desufflation slurry having the target density and the target half-life.
[0057] Specifically, the defloating slurry can be configured and obtained at the large-diameter directional drilling backhaul construction site, temporarily stored in a mud tank, and injected as needed.
[0058] Schematic diagram of horizontal directional drilling pipeline crossing and pulling back construction site Figure 7 .
[0059] In order to ensure that the pipeline is always suspended in the hole during the backhaul process, the target net buoyancy of the crossing pipe in the hole needs to be close to zero. In some embodiments of the present disclosure, the target net buoyancy is set to ±0.1 kN / m. The target net buoyancy of the crossing pipe in the hole can be close to zero by adjusting the density ratio of the debuoyancy slurry injected into the crossing pipe and the mud in the hole outside the crossing pipe.
[0060] Therefore, in order to make the target net buoyancy of the crossing pipe in the hole close to zero, it is necessary to adjust the density of the debuoyancy slurry according to the mud density in the hole outside the crossing pipe. At the construction site, for the convenience of calculation, the target density of the debuoyancy slurry is generally determined according to the target net buoyancy and mud density through the correspondence between the combination of the predetermined target net buoyancy and mud density and the target density of the debuoyancy slurry.
[0061] Figure 4 This is a calculation table for the density of the construction site deflocculation slurry shown in some embodiments of the present disclosure. Figure 4 As shown, the target density of the downsizing slurry (light color) is determined by the mud density in the through hole (light gray) and the target net buoyancy of the pipeline in the hole (dark gray).
[0062] At the same time, in order to ensure that the defloating effect will not be affected by the changes in the horizontal and longitudinal positions of the pipeline during the backhaul process, the density of the defloating slurry must remain stable during the backhaul process. Therefore, it is necessary to obtain the backhaul time in advance according to the construction plan, and then use the backhaul time as the target half-life of the defloating slurry. The density of the defloating slurry remains basically unchanged during the half-life.
[0063] The target density of the deflocculation slurry generally needs to be within (0.5g / ml-0.8g / ml), and the target half-life generally needs to be within (24-72 hours).
[0064] After the target density and the target half-life are determined, the target density and the target half-life can be achieved by adjusting the ratio of the deflocculation slurry.
[0065] In some embodiments of the present disclosure, adding soda ash to the basic ratio can increase the density of the slurry, extend the half-life of the slurry, and adjust the uniformity of foaming. At the same time, the ratio of the deflocculation slurry with a density and half-life matching the target density and target half-life can also be selected according to the density and half-life of different deflocculation slurry ratios obtained in advance in the experiment (such as Example 1, Example 2 and Example 3).
[0066] After the ratio of the deflocculation slurry is determined, the deflocculation slurry of the ratio can be stirred and foamed at a stirring speed of 2000 rpm at the construction site to obtain a deflocculation slurry with a target density and a target half-life. The finished product is temporarily stored in a mud tank for use.
[0067] Let the deflocculation slurry stand for a period of time and observe the stability of the deflocculation slurry before and after stirring and after standing. Figure 5 The experimental data show that the foam stability of the deflocculation slurry after stirring is good within the half-life period, and the data from all parties meet the construction requirements.
[0068] Some embodiments of the present disclosure disclose a method for lowering the float of a horizontal directional drilling pipeline during its crossing and backhauling. Figure 6 : is a flow chart of the floating reduction method. Figure 6 As shown, the method includes:
[0069] S610: According to Figure 3 The desaturation slurry is prepared by the method described in S310-S330.
[0070] S620: When the large-diameter directional drill is pulled back, the debuoyancy slurry is injected into the crossing pipe so that the net buoyancy of the crossing pipe in the hole is within ±0.1 kN / m.
[0071] Specifically, first measure the density of the mud in the hole outside the crossing pipe, and pre-configure the defloating slurry at the construction site according to the method described in S310-S330, and temporarily store it in the mud tank. The configuration time should be as close to the construction time as possible, not too far in advance.
[0072] Figure 7 This is a schematic diagram of a horizontal directional drilling pipeline crossing and pulling back construction site shown in some embodiments of the present disclosure. Figure 7 As shown, the large-diameter directional drilling rod 14 is waiting to be towed back in the crossing pipe 12, and the grouting pipe 10 is connected to the mud pump 5 and the mud tank 6 storing the defloating slurry through the mud high-pressure pipe 7, and the grouting pipe 10 is directly extended to the position of the pipeline towing head through the catback 11. The connection between the grouting pipe 10 and the mud high-pressure pipe 7 is provided with a flow valve 8 and a butterfly valve 9 to control the grouting speed of the defloating slurry.
[0073] At the beginning of the backhaul construction, the grouting pipe 10 starts to inject the defloating slurry 13 after the head of the grouting pipe 10 passes through the catback 11 and enters the dragging head position of the crossing pipe 12. The mud pump 5 drives the defloating slurry stored in the mud tank 6 to enter the grouting pipe 10 through the mud high-pressure pipe 7. The grouting speed and grouting amount of the defloating slurry 13 injected into the crossing pipe 12 are controlled by controlling the flow valve 8 and the butterfly valve 9 to ensure that the defloating slurry liquid level in the crossing pipe is always lower than the top of the catback 11.
[0074] After the back-pulling construction is completed, the pipeline can be cleaned by pigging.
[0075] In summary, the debuoyancy slurry, the preparation method of the debuoyancy slurry, and the debuoyancy method during the horizontal directional drilling pipeline crossing and backhauling provided by the embodiments of the present disclosure reduce the net buoyancy of the crossing pipe in the hole by injecting the debuoyancy slurry into the crossing pipe. Because the debuoyancy slurry is injected through the grouting system, the debuoyancy slurry can be configured in advance on site and injected as needed. After the construction is completed, the debuoyancy slurry can be removed by cleaning the pipe. The construction is quick and simple, and there is no need to install or disassemble the PE pipe, thereby significantly shortening the construction period and reducing costs. Because the net buoyancy of the crossing pipe can be reduced to basically 0 by adjusting the density of the debuoyancy slurry, it is ensured that the pipeline is always suspended in the hole during the backhauling process; the backhauling pipeline is filled with the debuoyancy slurry to form a solid overall stable structure, and the debuoyancy effect will not be affected by the horizontal and longitudinal position changes of the pipeline during the backhauling process; the starting position of the injection is in front of the cat's back, so that it can not only ensure that the pipeline towed into the hole is in a suspended state in the mud after grouting, but also ensure that the pipeline behind the cat's back floats on the water surface of the sending ditch, so that a more accurate debuoyancy effect can be obtained.
[0076] It should be understood that the above specific embodiments of the present disclosure are only used to illustrate or explain the principles of the present disclosure, and do not constitute a limitation of the present disclosure. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present disclosure should be included in the protection scope of the present disclosure. In addition, the claims attached to the present disclosure are intended to cover all changes and modifications that fall within the scope and boundaries of the attached claims, or the equivalent forms of such scope and boundaries.
Claims
1. A buoyancy-reducing slurry, used for injection into a crossing pipe to reduce the net buoyancy of a large-diameter directional drill during its pullback, characterized in that: The slurry ratio (weight percentage) is: water, bentonite (4%-6%), foaming agent (0.1%-0.3%) and stabilizer (0.05%-0.2%).
2. The slurry according to claim 1, characterized in that Also includes soda ash.
3. A method for preparing a deflocculation slurry, characterized in that: include: Determining a target density and a target half-life of the desludging slurry, wherein the density of the desludging slurry is stable within the target half-life; Adjusting the ratio of the deflocculation slurry according to claim 1 to achieve the target density and the target half-life; The deflocculation slurry of the proportion is stirred and foamed at a stirring speed of 2000 rpm to obtain the deflocculation slurry having the target density and the target half-life.
4. The method according to claim 3, characterized in that Determining the target half-life of the desludging slurry comprises: The target half-life is not less than the directional drilling backhaul time.
5. The method according to claim 3, characterized in that: Determining the target density of the deflocculation slurry comprises: The target net buoyancy of the crossing pipe in the hole is determined and the mud density in the hole outside the crossing pipe is obtained, and the target density of the debuoyancy slurry is determined based on the target net buoyancy and the mud density.
6. The method according to claim 3, characterized in that The method of adjusting the ratio of the deflocculation slurry according to claim 1 to achieve the target density and the target half-life comprises: Soda ash is added to the desaturated slurry, and the density and half-life of the desaturated slurry are increased by increasing the content of the soda ash until the target density and the target half-life are reached.
7. A floating method, applied to large-diameter directional drilling pipeline crossing and pulling back construction, characterized in that: include: The desludging slurry is prepared according to the method according to any one of claims 3 to 6; When the large-diameter directional drill is pulled back, the debuoyancy slurry is injected into the crossing pipe so that the net buoyancy of the crossing pipe in the hole is within ±0.1 kN / m.
8. The method according to claim 7, characterized in that The injecting of the deflocculation slurry into the crossing pipe comprises: When the large-diameter directional drill is towed back, the grouting pipe head is passed through the catback into the crossing pipe and then the defloating slurry is injected into the crossing pipe through the grouting pipe head.
9. The method according to claim 8, characterized in that The injecting of the deflocculation slurry into the crossing pipe through the grouting pipe head comprises: The grouting pipe is extended into the position of the pipeline pulling head for fixed-point grouting.
10. The method according to claim 7, characterized in that The injecting of the deflocculation slurry into the crossing pipe further comprises: By controlling the grouting speed and grouting amount, it is ensured that the liquid level in the crossing pipe is always lower than the cat back apex.